SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9dc8d9dff63faa9bfbab097ccadd059719822d48a4fa0e078378b786db698de5' 
  AND token = 'fIdl1J1VPsn7ugbE+qIZ7BkIz1aQ+EqrRrkMTFpu6cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}